Railway traffic controlling apparatus



April 28, 1942. E. E. PARRILL RAILWAY TRAFFIC CONTROLLING APPARATUS Filed March 25, 1941 m w I. h n o m H E Patented Apr. 28, 1942 RAILWAY TRAFFIC CONTROLLING APPARATUS Easton E. Parrill. Swissvale, Pa., assignor to The Union Switch & Signal Company, Swissvale, Pa... a corporation of Pennsylvania Application March 25, 1941, Serial No. 335,040

7 Claims. (01. 246-39) My invention relates to railway traffic controlling apparatus, and more particularly to train governing apparatus controlled according to the speed at which a train approaches a designated locality.

When a train approaches the end of a track 1 within station limits, or approaches the dead end of a track, a speed restriction for the train is required in order to avoid possible overrunning of the track limits. Likewise at grades, congested territory and like locations, it is desirable that the speed of a train passing through a track section in the approach to such a location be at or below a predetermined value. In other words, it is desirable. that at least a predetermined period of time be consumed by a train in passing through a track section in the approach to a track hazard in order that a proceed condition of the signaling devices governing the movement of the train at such track hazard. .be efiected.

Accordingly, a feature of my invention is the provision of railway traflic controlling apparatus incorporating novel and improved means for controlling train governing devices according to the:

speed at which a train approaches a designated station or location.

Another feature of my invention is the provision of novel and improved means for requiring that a train consume a predetermined period of r time or more in moving through a given track section in order that a signaling device governing the entrance of the train into another track section in advance be operated to a proceed position.

Again a feature of my invention is the provision of novel and inexpensive railway trafiic controlling apparatus of the type here contemplated for operating a time element relay when a train occupies the rear track section of two successive sections and for including contacts of such time element relay in the operating circuits of an automatic train stop and signal associated with the advance section of such two sections. and the usual control relays now provided are not required. Such time element relay is used to determine that a train consumes at least a predetermined period of time in traversing the rear track section.

Still another feature of my invention is the provision of novel and inexpensive means for railway traffic controlling apparatus of the type here involved wherewith a signal governing traffic in the rear section of two sections can be operated to a proceed position only if the signal governing traific in the advance section of the two sections displays a stop indication.

The above features, as well as other advantages of my invention which will appear as the specification progresses, are attained according to my invention by providing a time element relay having a check contact closed only when the relay occupies its initial position and front and back contacts which are operated after the relay has been energized for a preselected time interval, circuit means for energizing such relay, and train governing devices governed by the relay. Such circuit means is controlled by the track relays of each of two successive track sections and by an automatic train stop associated with the advance section of the two track sections. The operating circuit of the automatic train stop and the operating circuitof a signal for the advance section include front contacts of the time element relay. A signal for the rear section of such two track sections is controlled over the check contact 'of the time element relay and hence the signal for the advance section displays stop in order for the signal of the rear section to display a proceed position.

I shall describe one form of apparatus embodying by invention and shall then point out the novel features thereof in claims.

The accompanying drawing is a diagrammatic view showing one form of apparatus embodying my invention when used for governing an automatic signal and an automatic train stop for a stretch of railway approaching a track hazard such as, for example, a station or a descending grade or a congested territory.

Referring to the drawing, the reference characters la and lb designate the track rails of a stretch of railway and which rails are formed by the usual insulated rail joints into consecutive track sections of a signal system and of which track sections only three sections A-B, B-C and (3-D are shown since these are sufficient for a full understanding of my invention. These track sections may be those in the approach to a station or to a location of congested traflic or to a descending grade. The significant point about such stretch of railway track is that restricted speed is required for a train moving through these sections in the normal direction of travel as indicated by an arrow.

Each section is provided with a signal designated by the reference character S plus a suffix corresponding to the location of the signal. These signals may be of'any one of the several types commonly used. In the present embodiment of my invention these signals are color light signals each of which is capable of displaying a yellow lamp Y for 2. proceed indication and a red lamp R for a stop indication.

Automatic train stops TB and TC are located at the entrance of sections BC and -D, respectively. These automatic train stops may be any one of several well-known types and are shown by the usual conventional symbol. Such train stops may be, for example, of the twoposition type covered by Letters Patent of the United States No. 1,775,811, granted September 16, 1930, to John P. Coleman, for Railway traffic controlling apparatus. It is sufiicient for this application to point out that the trackway element of such train stop is operated to a vertical or stop position and to a horizontal or clear position. It is preferably moved to its stop position by a biasing spring or by gravity or by both, and to its clear position by a suitable power mechanism controlled by an electric circuit. The function of the trackway element for such train stop is to cooperate with a train-carried element, the arrangement being such that the train-carried element is effective to cause the shutting oif of the propelling power or the application of the train brakes, or both, if the train should attempt to pass the trip arm of the trackway element when such trip arm is raised to its stop position to engage the train-carried element. When the trip arm is lowered to its clear position, the train-carried element is not engaged as the train passes the trip arm. and the train is unimpeded. Each train stop TB and TC is provided with a circuit controller which is operatively connected therewith as indicated by dotted lines 4 and 5, respectively. Thus contacts 6, l and B of a circuit controller are operated to the positions illustrated by the solid lines in the drawing when the train stop TB is set at its stop position, that is to the position shown in the drawing, and are operated to the positions illustrated by dotted lines when the train stop is set at the clear position. In like fashion contacts 9, l0 and II are operated to the positions illustrated by the solid lines in the drawing when train stop TC is set at the stop position and are operated to the positions illustrated by the dotted lines in the drawing when the train stop TC is set at the clear position- Each track section A--B, BC and C-D is provided with a track circuit including a current source connected across the rails at one end of the section and a track relay connected across the rails at the other end of the section. In the present case alternating current track circuits are provided, the track relay being indicated by the reference character TR plus a prefix corresponding to the location of the relay and each current source being a transformer indicated by the reference character T plus a pre fix corresponding to its location.

The operating circuits for signal SA are controlled by a signal control relay S-AI-I, the operating circuits for signal SB and its associated train stop TB are governed by a time element relay BTE, and the operating circuits of signal SC and its associated train stop TC are governed by a time element relay CTE. Relay SAH is an alternating current relay of the usual type. Time element relays BTE and CTE are preferably alike and may be any one of the several types well known to the art and may be, for example, alternating current time element relays covered by United States Letters Patent No. 1,272,972, granted July 16, 1918, to L. V. Lewis, for Circuit controllers. Looking at time element relay BTE, when the relay is deenergized, it is biased to an initial position where a check contact I2 is closed and its contact members it, Hi, l5, l6 and i! are in engagement with back contacts, the back contacts i8 and I9 associated with contact members it and ii, respectively, being the only ones shown in the drawing. When an operating winding 20 of the relay is energized, check contact I2 is immediately opened and remains open until such time as winding 2% is deenergized and the contact mechanism of the relay again assumes the initial position. When winding 20 is energized for a preselected time interval of say, for example, 25 seconds, the contact members 13 to H, inclusive, are moved from engagement with their respective back contacts to engagement with respective front contacts of which iront contacts only the front contacts 2|, 22 and 23 associated with contact members [3, Hi and I5, respectively, are shown in the drawing. As stated hereinbefore, time element relay CTE is preferably similar to BTE and further description 0 relay CTE is not required. Signal control relay SAH when picked up closing front contact M, completes an obvious operating circuit for the proceed lamp Y of signal SA and when relay SAH is released closing back contact 25 an obvious operating circuit is completed for stop lamp R of signal SA, these operating circuits being connected to any convenient source of current, such as a source of alternating current whose terminals are indicated at BX and CK. Relay SAH is in turn energized over a circuit including terminal BX of the current source, check contact l2 of time element relay BTE, back contact lll9 of relay BTE, front contact 28 of track relay ATR, winding of relay SAH and terminal CX of the current source. Time element relay BTE is energized by a circuit that can be traced from terminal BX over back contact 2i3-2l of relay CTE, check contact 29 of relay CTE, front contacts 30 and 3! of track relays CTR and BTR, respectively; back contact 32 of track relay ATR, contact 5 of the controller for automatic train stop TB closed at the stop .position, and winding 29 of relay BTE to terminal CX. Relay BTE when energized for its pre selected operating period closes front contact l32l, and completes a stick circuit path for by-passing this energizing circuit around contact 5 of train stop TB. In the case train stopTB is set at its stop position and relay BTE is deenergized to occupy its initial position, an operating circuit is formed including terminal BX, back contact I6lli of relay BTE and contact 8 of the controller of train stop TB in multiple, stop lamp R of signal SB and terminal OK, and signal SB is operated as required to display a stop indication. Train stop TB is provided with a simple operating circuit including front contact M-22 of time element relay B'I'E in multiple with back contact 58 of track relay BTR. With relay BTE operated to close its front contact i5-23 and train stop TB operated to its clear position to close contact I, an operating circuit is formed from terminal BX over front contact l52 3, contact '5, and lamp Y to terminal OK, and signal SB is operated as required to display a proceed indication.

I Time element relay CTE is energized over a circuit including back contact 33 of track relay BTR, front contact 34 of track relay CTR and contact 9 of the controller of train stop TC in its stop position. Relay CTE when thus energized for a preselected time interval to close front contact 35-36 completes a stick circuit path which by-passes the energizing circuit for the relay around contact 9 of the circuit controller of the automatic train stop TC. When relay C'IE is set at its initial position to close back contact 31-38, or when train stop TC is set at its stop position to close contact I I, an operating circuit is formed for lamp R of signal SC as will be readily understood from an inspection of the drawing, contacts 31-38 and II being included in the circuit in multiple. The operating circuit for train stop TC includes front contact 39-40 of time element relay C'IE in multiple with back contact 5| of track relay CTR. Also a proceed operating circuit for signal SC can be traced from terminal BX over front contact -42 of relay CTE, contact of the controller for train stop TC closed at the clear position, lamp Y of signal SC and to terminal CX.

Normally, that is, when sections A-B, B-C and CD are unoccupied, the track relays are all picked up, time element relays BTE and CTE are deenergized causing the respective signals SB and SC to display the stop indication and the respective train stops TB and TC to be set at the stop position, and signal control relay SAH is picked up to operate signal SA as required to display its proceed indication.

Since relay SAH is energized over a circuit including check contact 12 and back contact 11-49 of relay BTE, it is to be noted that signal SB'is operated to display its stop indication and train stop TB is operated to its stop position before signal SA can be operated to display its proceed indication.

In the case a train moving in the normal direction of trafiic enters section A-B to shunt track relay ATR, the energizing circuit for time element relay BTE is closed and that relay is operated to at once open check contact l2 and then to move its contact members I3 to I1, inclusive, at the end of the operating period preselected for that relay. -When relay BTE is operated to close its front contacts the operating circuit for train stop TB is closed at front contact I 4-42 and the train stop is lowered to its clear position, relay BTE being retained energized over its stick circuit path after contactfi is opened at the clear position of the stop. It is to be noted that the operating circuit for stop lamp R for signal SB is retained closed at contact member 8 of train stop TB after relay BTE is operated until the train stop is subsequently moved to its clear position. With time element relay BTE operated to close its front contact I23 and train stop TB operated to its clear position closing contact I of the corresponding circuit controller, the operating circuit for proceed lamp Y of signal B is closed and that lamp is illuminated to display a proceed indication. It follows that the train must consume a time interval at least equal to the operating time of time element relay BTE in traversing section A-B in order for it to receive a proceed signal at signal SE to enter section B-C, and in order to avert an automatic brake application as effected through train stop TB in the event the train enters the section BC before the stop TB is moved to its clear position. In other words, the speed of the train must not exceed the prescribed average speed in traversing section A-B and which speed would of course be that safe for the train to approach sections B--C and CD due to the hazards associated with such sections.

The train upon entering section B-C to shunt track relay BTR. completes the energizing circuit for time element relay CTE and that relay is energized to at once open check contact 29 and then to move its contact members to close front contacts at the end of the operating time preselected for that relay. The shunting of track relay BTR. opening front contact 3| deenergizes relay BTE and that relay is immediately released to its initial position causing signal SB to be operated to its stop position, and one path of the operating circuit of the train stop TB to be opened, train stop TB being now retained at the clear position over the path of its operating circuit including back contact 50 of relay BTR. With relay CTE operated to close front contact 39-40, the train stop TC is operated to its clear position, relay CTE being retained energized over the stick circuit path subsequent to the train stop TC being lowered to the clear position. Train stop TC when operated to its clear position closing contact I0 completes the operating circuit for proceed lamp Y of signal SC and signal SC is operated as required to display a proceed indication. Consequently the train must consume in section B--C a time interval at least equal to the preselected operating time of relay CTE inorder to receive a proceed indication at signal SC for entering section CD and in order to avoid a brake application as effected by train stop TC. That is, the speed of the train in section B-C must not exceed the prescribed average speed consistent with the track hazard of section CD.

The train upon entering section CD shunts track relay CTR to open front contact 34 and deenergize relay CTE which relay restores to its initial position where the operating circuit for proceed lamp Y of signal SC is opened and the circuit for lamp R. of signal SC is closed causing signal SC to display a stop indication. Train stop TC is now held at its clear position over the path of its operating circuit including back contact 5! of relay CTR. The train by vacating section CD permits track relay CTR to be picked up and the apparatus is then restored to its normal position.

It is to be seen therefore that I have provided novel and improved means wherewith the operating circuits of a signal and of a train stop are completed over contacts of a time element relay and the usual control relays for such signal and train stop are not required. Also there is here provided improved means wherewith the speed of a train as it approaches a location of a track hazard is governed. Again, a proceed indication of a signal for a track section in an approach to a track hazard is operated to display a proceed indication only when the signal and train stop for the section in advance are set at stop. It is to be noted that train stops TB and TC are retained at the clear position when the respective track section is occupied in order that they may be cleared for trains moving against the normal direction of trafiic.

Although I have herein shown and described only one form of railway trafiic controlling apparatus embodying my invention, it is understood that various changes and modifications may be made therein within the scope of the appended claims without departing from the spirit and scope of my invention.

Having thus described my invention, what: I claim is:

1. In combination, a stretch of railway formed with a first and a second track section which a train travels in the order named when operating in the normal direction of traffic, a signal and an automatic train stop located at the entrance of the second section to govern trafilc entering that section, a track relay for each of said sections, atime element relay provided with front contacts which are closed only after the relay has been energized for. a preselected time interval; an energizing circuit including a contact operatively connected to said automatic train stop and closed in the stop position, a back contact of the track relay for said first section and afront contact of the track relay for said second sectionto energize said time element relay; a first operating circuit including a front contact of said time element relay for operating said train stop to a clear position, and a second operating circuit including a front contact of said time element relay and a contact operatively connected to said train stop and closed at the clear position for operating said signal as required to display a proceed indication.

2. In combination, a stretch of railway formed with a first and a second track section which a train travels in the'order named'when operating in the normal direction of traffic, a signal and an automatic train stop located at the entrance of the second section to govern trafiic entering that section, a track relay for each of said sections, a time element relay provided with front contacts which are closed only after the relay has been energized for a preselected time interval; an energizing circuit including a contact operatively connected to said automatic train stop and closed in the stop position, a back contact of the track relay for said first section and a front contact of the track relay for said second section to energize said time element relay; a stick circuit path including a front contact of said time element relay to by-pass said energizing circuit, around said contact of the automatic train stop, a first operating circuit including a front contact of said time element relay for operating said train stop to a clear position, and a second operating circuit including a front contact of said time element relay and a contact operatively connected to said train stop and closed at the clear position for operating said signal as required to display a proceed indication.

In combination, a stretch of railway formed with a first and a second track section which a train travels in the order named when operati-ng'in the normal direction of traffic, a signal and an automatic train stop located at the entrance of the second section to govern traffic entering that section, a track relay for each of said sections, a time element relay provided with contact members which are operated from respective back to respective front contacts only after the relay has been energized for a preselected time interval; an energizing circuit including a contact operatively connected to said train stop and closed at the stop position, a back contact of the track relay for said first track section and a front contact of the track relay for said second track section to energize said time element relay; a stick circuit path including a front contact of said time element relay toby-pass said energizing circuit around said contact of the train stop, a first operating circuit including in multiple a back contact of the time element relay. and .a contact operatively connected to. the train stop and closed at. the stop position to operate the signal as required to display a stopindication, a second'operating circuit including a front contact of the time element relay to operate said train stop to a clear position, and a third operating circuit including in series a front contact of the time element relay and a contact operativelyconnected to the train stop and closed at the clear position to operate said signal as required to display a proceed indication.

4. In combination, a stretch of railway formed with a first and a second track section which a train travels in the order named when'operating in the normal direction of traffic, an automatic train stop located at the entrance of said second section to govern a train entering such section, a track relay for each of said sections, a time element relay provided with front contacts which are closed only after the relay has been energized for a preselected time interval; an energizing circuit including a contact operatively connected to said train stop and closed at the stop position, a back contact of the track relay for the first section and a front contact of the track relay for the second section to energize said time element relay; a stick circuit path including a front contact of the time element relay to by-pass said energizing circuit around said train stop contact, and an operating circuit including a front contact of said time element relay to operate said train stop to a clear position.

5. In combination, a stretch of railway formed with a first and a second track section which a train travels in the order named when operating in the normal direction of traffic, a train governing device located at the entrance of said second section and operable to a stop and a clear position for governing the entrance of a train into that section, a track relay for each of said sections, a time element relay provided with contact members operable from a back to a front contact only when the relay has been energized for a preselected time interval; an energizing circuit including a contact operatively connected to said train governing device and closed at the stop position, a back contact of the track relay for said first section and a front contact of the track relay for said second section to energize said time element relay; a stick circuit path including a front contact of said time element relay to by-pass said energizing circuit around the contact of said time governing device, and an operating circuit including a front contact of said time element relay for operating said device to its clear position.

6. In combination, a stretch of railway formed with a first and a second track section which a train travels in the order named when operating in a normal direction of travel, a signal located at the entrance of each of said sections and operable to a stop and a clear position for governing the entrance of a train into the respective section, a track relay for each of said sections, a time element relay provided with a check contact closed at the initial position of the relay and with contact members which are operated from a back contact to a front contact only after the relay has been energized for a preselected time interval, an energizing circuit including a back contact of the track relay for said first section and a front contact of the track relay for said second section to energize said time element relay, a first operating circuit including a back contact of said time element relay to operate the signal for the second section to its stop position, a second operating circuit including a front contact of said time element relay to operate the signal for the second section to its clear position, and means including said check contact to operate the signal for the first section to its clear position.

7. In combination, a stretch of railway formed with a first, a second and a third track section which a train travels in the order named, a signal for each section to govern traffic therethrough, a track relay for each section, a first and a second time element relay each provided with a check contact closed only when the relay is in its initial position and front contacts closed only after the relay has been energized for a preselected time interval; a first energizing circuit including a back contact of the track relay of the first section, a front contact of the track relay of each of the second and third sections, and the check contact of said second time element relay to energize said first time element relay; a second energizing circuit including a back contact of the track relay for said second section and a front contact of the track relay for said third section to energize said second time element relay, means including the check contact of said first time relay and a front contact of the track relay for said first section for controlling the operating circuits of the signal for said first section, means including a front and a back contact of the first time element relay for controlling the operating circuits of the signal for said second section, and means including a back and a front contact of said second time element relay for controlling the operating circuits of the signal for said third section.

EASTON E. PARRILL. 

